Egg surface morphology, development, and evolution in the Congrogadinae (Pisces: Perciformes: Pseudochromidae)

1990 ◽  
Vol 68 (5) ◽  
pp. 923-934 ◽  
Author(s):  
Randall D. Mooi ◽  
Richard Winterbottom ◽  
Mary Burridge
Keyword(s):  
Surface Morphology ◽  
Egg Size ◽  
Maximum Diameter ◽  
Egg Mass ◽  
Sea Grass ◽  
Final Length ◽  
Morphology Development ◽  
Deep Pits ◽  
Shape Changes ◽  
Development And Evolution

The Congrogadinae consists of 19 species of elongate fishes which reach a maximum length of about 40 cm. They occur primarily in the coral reefs and sea-grass meadows of the Indo-West Pacific. Mature ovarian eggs were found to possess hooked, multi-armed projections distributed equidistantly over their surfaces. Each projection has a central pedicel perpendicular to the chorion which raises it above the egg surface. A few of these hooks give rise to long filaments. The numbers of hooks, arms per hook, and filaments vary among taxa. Hook size and shape changes with egg size. On eggs 70 μm in diameter, hooks begin as small, button-shaped knobs about 2 μm across, gradually becoming stalked and composed of four V-shaped subunits. These eventually form a cruciform structure, about 200 μm across, which bears recurved hooks; these occur on eggs over 3000 μm in diameter. Hooks stop increasing in size before the egg attains its maximum diameter. Filaments increase in length as the hooks grow, reaching a final length of at least 7500 μm. In extruded eggs, the filaments (but not the hooks) come loose from the chorion to tangle with the hooks and filaments of adjacent eggs. This forms an egg mass which is probably guarded by the male. Although the data are prone to homoplasy, two alternative cladograms based on egg surface morphology were constructed. Changes to cladograms existing in the literature involved the genera Halimuraena, Haliophis, Halidesmus, and Blennodesmus. These genera might be monophyletic, based on the occurrence of the hooks in deep pits. The monophyly of the subgenus Congrogadoides is further corroborated by the predominance of three-armed hooks on their egg surfaces.

Texture and Surface Morphology Development in Zinc and Zinc-Cobalt Electrodeposits

2008 ◽  
Vol 155 (12) ◽  
pp. D783 ◽  
Author(s):  
K. Raeissi ◽  
A. Tufani ◽  
A. Saatchi ◽  
M. A. Golozar ◽  
J. A. Szpunar
Keyword(s):  
Surface Morphology ◽  
Morphology Development

scholarly journals Influence of heavier impurity deposition on surface morphology development and sputtering behavior explored in multiple linear plasma devices

2019 ◽  
Vol 18 ◽  
pp. 67-71 ◽  
Author(s):  
D. Nishijima ◽  
A. Kreter ◽  
M.J. Baldwin ◽  
D. Borodin ◽  
A. Eksaeva ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Morphology Development ◽  
Linear Plasma

scholarly journals Egg Size, Eggshell Porosity, and Incubation Period in the Marine Bird Family Alcidae

The Auk ◽  
2007 ◽  
Vol 124 (1) ◽  
pp. 307-315
Author(s):  
Karen Zimmermann ◽  
J. Mark Hipfner
Keyword(s):  
Incubation Period ◽  
Egg Size ◽  
Interspecific Variation ◽  
Egg Mass ◽  
Proximate Mechanisms ◽  
Diffusion Limited ◽  
Evolutionary Changes ◽  
Incubation Periods ◽  
Avian Incubation ◽  
Embryonic Metabolism

Abstract Although the ultimate factors that influence the duration of avian incubation periods are well known, we know much less about the proximate mechanisms by which birds adjust incubation period in response to selection. We tested the hypothesis that an adjustment in eggshell porosity is one such proximate mechanism (i.e., that avian species with higher ratios of incubation period to egg size lay eggs with less porous shells). Eggshell porosity affects the rate of gaseous exchange between the developing embryo and the external environment; thus, to the extent that embryonic metabolism is diffusion-limited, eggshell porosity could directly determine incubation period. To test that hypothesis, we collected eggs from seven species of Alcidae, a family of marine birds that exhibits an unusual degree of interspecific variation in incubation period, and measured egg mass and eggshell porosity (determined by the number and size of pores and the thickness of the shell). Incubation periods were obtained from the literature. Egg mass and eggshell porosity combined explained 87% of the variation in incubation period among the seven species, which included at least one member of each of the six main alcid lineages. As predicted, eggshell porosity and incubation period were negatively related, after controlling for egg mass. Our results are consistent with the hypothesis that evolutionary changes in avian incubation period may be attributed, at least in part, to adjustments in eggshell porosity. Taille de l’Œuf, Porosité de la Coquille et Période d’Incubation chez les Oiseaux Marins de la Famille des Alcidés

Annual variations in reproductive characteristics of painted turtles (Chrysemys picta)

1986 ◽  
Vol 64 (5) ◽  
pp. 1148-1151 ◽  
Author(s):  
Lin Schwarzkopf ◽  
Ronald J. Brooks
Keyword(s):  
Body Size ◽  
Clutch Size ◽  
Repeated Measures ◽  
Egg Size ◽  
Annual Variation ◽  
Egg Mass ◽  
Annual Variations ◽  
Painted Turtles ◽  
Sources Of Variation ◽  
Clutch Mass

In Algonquin Park, Ontario, body size and clutch characteristics were recorded for 51 female painted turtles (Chrysemyspicta) in 1983, 61 in 1984, and 24 in 1985. Clutch size, clutch mass, and egg width correlated significantly with body size (carapace length) in all 3 years. Egg length and egg mass were significantly related to body size in 1984 and 1985, but not in 1983. There were no significant correlations of egg width or egg mass to clutch size. For a group of the same individuals compared by repeated-measures ANOVA, mean clutch mass and mean egg size, but not mean clutch size, varied significantly among years. Correlation of egg size with body size, lack of correlation between egg size and clutch size, and annual variation in egg size, but not clutch size, all fail to support current versions of optimal egg size theory. Twenty-six females nested in both 1983 and 1984 and 11 females nested in both 1984 and 1985. Fourteen females nested twice in 1 year: six in 1983 and eight in 1984. Between 43 and 73% of adult females nested in a given year and 12–13% nested twice in a single season. These estimates are similar to those reported for other populations of this species. It appears that variations in both clutch size (frequency) and egg size are important sources of variation in reproductive output.

The annual reproductive cycle of the black prickleback, Xiphister atropurpureus, a Pacific Coast blennioid fish

1974 ◽  
Vol 52 (7) ◽  
pp. 795-802 ◽  
Author(s):  
John P. Wourms ◽  
David Evans
Keyword(s):  
Reproductive Cycle ◽  
Egg Size ◽  
Gonad Index ◽  
Egg Mass ◽  
Base Line ◽  
Annual Reproductive Cycle ◽  
Intertidal Habitat ◽  
Spawning Period ◽  
Egg Number ◽  
Xiphister Atropurpureus

Semimonthly determinations of the gonad index made during the course of a year show that Xiphister atropurpureus has an annual reproductive cycle. The gonad index (ovary) increases during midwinter, attains a maximum value of 20 in late April–May, and declines to a base-line value of 0.5 from June to December. Spawning occurs during a 6-week period in late April–May. Spawning takes place in zone 4 of the intertidal habitat. Eggs deposited singly are fertilized and then shaped into a spherical mass by the parents. As egg envelopes harden, they adhere to one another to form a coherent mass. The egg mass is guarded by one or both parents. The annual reproductive cycle is considered to be a necessary consequence of the energetic demands of oogenesis combined with selection for a spawning period which is environmentally optimal. Alternative cycles based on modification of the present egg size (large)/egg number (few) relationship do not appear feasible, since the required modification of the egg size/egg number ratio would be selectively disadvantageous. The intertidal habitat of Xiphisier is subject to several potential environmental hazards: wave shock, reduced salinity due to rain and runoff, and excessively high or low temperatures. These are seasonal hazards which occur during winter or summer. Spawning is timed (April–May), so the probability that developing eggs will be exposed to environmental risks is minimized while the probability of exposure to environmental benefits is maximized. It is suggested that the reproductive cycle is under photoperiodic control.

Egg-size variation in Yellow Warblers: apportionment of parental investment and the brood-survival hypothesis

1993 ◽  
Vol 71 (5) ◽  
pp. 1008-1011 ◽  
Author(s):  
Percy N. Hébert ◽  
Spencer G. Sealy
Keyword(s):  
Egg Size ◽  
Survival Rates ◽  
Size Variation ◽  
Relative Mass ◽  
Egg Mass ◽  
Passerine Birds ◽  
Dendroica Petechia ◽  
Brood Survival ◽  
Yellow Warblers ◽  
Clutch Initiation

It has been hypothesized that in passerine birds the larger size of last-laid eggs is part of a brood-survival strategy. We examined the usefulness of the brood-survival hypothesis in explaining intraclutch variation in egg mass of Yellow Warblers (Dendroica petechia). In 4- and 5-egg clutches, egg mass increased significantly with laying order. Although last-hatched nestlings in broods of 4 had higher survival rates than their counterparts in broods of 5, there were no differences in the absolute or relative mass of last-laid eggs in clutches of 4 and 5 eggs. In addition, the mass of last-laid eggs that hatched but did not produce a fledgling was not significantly different from that of last-laid eggs that did produce a fledgling. Finally, the relative mass of last-laid eggs was also not correlated with hatch spread or with date of clutch initiation. The results of this study do not support the brood-survival hypothesis.

Within-clutch egg-size variation in a subsocial bug: the positional effect hypothesis

2006 ◽  
Vol 84 (11) ◽  
pp. 1540-1544 ◽  
Author(s):  
Shin-ichi Kudo
Keyword(s):  
Predation Risk ◽  
Clutch Size ◽  
Egg Size ◽  
Size Variation ◽  
Instar Nymph ◽  
Offspring Size ◽  
Egg Mass ◽  
Female Body Size ◽  
Positional Effect ◽  
Effect Hypothesis

If there are differences in predation risk among the offspring within a clutch, parents should allocate less resources to the offspring facing higher risk. Predation risk, and thus offspring size, may depend on the spatial position of individual offspring within a clutch. To test this positional effect hypothesis, I examined egg-size (egg-mass) variation in the subsocial bug Elasmucha signoreti Scott, 1874 (Hemiptera: Acanthosomatidae). In subsocial insects, including Elasmucha , in which females guard their clutches against predators by covering the clutch with their bodies, there are large differences in survival between offspring at the centre and at the periphery of the clutch. There was considerable variation in reproductive output among females; female body size was positively correlated with egg mass but not with clutch size. Females laid significantly lighter eggs in the peripheral, and thus more vulnerable, part of the clutch. No phenotypic trade-off between egg mass and clutch size was detected. Egg mass was positively correlated with hatched first-instar nymph mass. Thus, E. signoreti females seem to allocate their resources according to the different predation risks faced by the offspring within a clutch. I suggest that the positional effect hypothesis can generally be applicable to species whose females lay eggs in clutches and that the eggs suffer different mortality rates which depend on their spatial positions within the clutch.

scholarly journals Reproductive traits of the gray ratsnake Ptyas korros from three geographically distinct populations

2012 ◽  
Vol 58 (6) ◽  
pp. 820-827 ◽  
Author(s):  
Long-Hui Lin ◽  
Fei Mao ◽  
Ce Chen ◽  
Xiang Ji
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Reproductive Output ◽  
Reproductive Traits ◽  
Egg Laying ◽  
Laying Date ◽  
Egg Mass ◽  
Size Number ◽  
Female Reproductive Traits ◽  
Clutch Mass

Abstract We collected gravid gray rat snakes Ptyas korros from three geographically distinct populations in China, Chenzhou (CZ), Jiangshan (JS) and Dinghai (DH), to study geographical variation in female reproductive traits. Egg-laying dates differed among the three populations such that at the most northern latitude egg-laying was latest, and earliest at the most southern lati-tutde. Clutch size, clutch mass, egg mass, egg shape, within clutch variability in egg sizes and relative clutch mass differed among the three populations, whereas post-oviposition body mass did not. Except for egg-laying date, none of the traits examined varied in a geographically continuous trend. CZ and DH females, although separated by a distance of approximately 1100 km as the crow flies, were similar in nearly all traits examined. JS females were distinguished from CZ and DH females by their higher fecundity (clutch size), greater reproductive output (clutch mass) and more rounded eggs. Our data do not validate the prediction that larger offspring should be produced in colder localities. The absence of an egg size-number trade-off in each of the three populations presumably suggests that P. korros is among species where eggs are well optimized for size within a population.

Surface morphology development of anodic oxide coatings on aluminium by low energy ion bombardment

Vacuum ◽  
1990 ◽  
Vol 40 (1-2) ◽  
pp. 153-156 ◽  
Author(s):  
Ž Bogdanov ◽  
M Milić ◽  
N Popović ◽  
T Nenadovi'c ◽  
D Peruško
Keyword(s):  
Surface Morphology ◽  
Ion Bombardment ◽  
Anodic Oxide ◽  
Low Energy ◽  
Oxide Coatings ◽  
Morphology Development
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